Abstract: A hydrogen generation apparatus including: a first desulfurizer; a second desulfurizer; a reformer to generate a hydrogen-containing reformed gas from a raw material gas from which sulfur has been removed by at least one of the first desulfurizer and the second desulfurizer; and a recycle passage through which a part of the reformed gas generated by the reformer is mixed into the raw material gas to be supplied to the second desulfurizer. After installation or maintenance of the hydrogen generation apparatus, the raw material gas is supplied to the reformer through the first desulfurizer until a catalyst in the second desulfurizer is activated by a mixed gas of the reformed gas supplied through the recycle passage and the raw material gas, and after the catalyst in the second desulfurizer is activated, the raw material gas is supplied to the reformer through the second desulfurizer.

Abstract: In a fuel cell system including a fuel cartridge and a fuel supply module, the fuel cartridge includes at least two ports, wherein a first port from among the at least two ports is a fuel inlet port and a second port from among the at least two ports is a fuel outlet port. The fuel cartridge may also include a fuel pouch or the fuel cartridge itself may be the fuel pouch. The fuel supply module may include a fuel circulation structure that circulates the fuel before the fuel is supplied to the stack. The fuel cell system may be equipped with an electronic apparatus and serve as a source of power.

Abstract: A system has a fuel cell with an anode, a membrane, and a cathode. A source of fuel passes along the anode and a source of an oxygen containing gas passes along the cathode. A downstream line captures fuel downstream of the anode and a separator separates impurities from the fuel on the downstream line, and recirculates fuel downstream of the separator for passage across the anode. A method of mixing air with an oxygen concentrated gas is also disclosed.

Abstract: A method for determining a rate of accumulation of nitrogen in an anode side of a fuel cell stack. The method includes determining a concentration of nitrogen in an anode loop and determining a number of moles of nitrogen in the anode loop. The method also includes determining a rate of accumulation of nitrogen in the anode loop and determining a permeability factor of nitrogen through fuel cell membranes in the fuel cell stack using the determined rate of accumulation of nitrogen in the anode loop.

Abstract: A fuel cell startup apparatus and method reduces high-voltage generation and corrosion of a cathode electrode that may occur because the density of oxygen is locally high in a cell near a central flow distributor after long-term parking of a fuel-cell vehicle. To this end, density control gas is selectably injected into a fuel supply line prior to supply of reaction gas of hydrogen and air in a fuel cell startup process after long-term parking to forcedly mix anode-side gas in the fuel supply line and the cell with the density control gas.

Abstract: A combined power generation system is promptly activated, and stable operation thereof is provided. A control apparatus of the combined power generation system that generates power by performing cooperative operation combining an SOFC and an MGT, in which the combined power generation system includes: an exhaust fuel gas supply line that supplies exhaust fuel gas to a combustor of the MGT from the SOFC; a recirculation line that branches from the exhaust fuel gas supply line to flow the exhaust fuel gas to the SOFC; and a flow rate adjustment valve provided on a path of the exhaust fuel gas supply line, and in which a gain to an opening of the flow rate adjustment valve is adjusted according to an cooperative operation state of the SOFC and the MGT.

Abstract: The present invention relates to a method for operating a fuel cell system, wherein the fuel cell system comprises at least one reformer for generating a reformate gas and at least one fuel cell for generating an electric current. An increased lifespan for the anode is achieved when with said anode an anode state value is continuously determined which correlates to a current degree of loading with carbon of the anode of the at least one fuel cell and when depending on the anode state value an oxygen-carbon ratio is varied in the reformate gas which is fed to the anode of the respective fuel cell.

Abstract: Various hot box fuel cell system components are provided, such as heat exchangers, steam generator and other components.

Abstract: A fuel cell system of the present invention includes: a reformer (1) configured to generate a hydrogen-containing fuel gas from a material gas and steam; a fuel cell (101) configured to generate electric power by using a fuel gas supplied from the reformer (1); a water tank (3) configured to store water; a water utilizing device configured to utilize the water supplied from the water tank (3); a first water supply unit (5) disposed on a water passage (30) extending from the water tank (3) to the water utilizing device and configured to supply the water in the water tank (3) to the water utilizing device; and a purifier (4) disposed on the water passage (30) and configured to purify the water flowing through the water passage (30), and the purifier (4) is provided such that when a water level of the water tank (3) is a full water level, the purifier (4) is filled with the water by the weight of the water.

Abstract: A fuel cell stack includes a heat exchange unit that performs heat exchange between a gas mixture containing source hydrogen and a circulating gas and cooling water used for controlling the temperature of the fuel cell stack. A system controller adjusts the temperature of the cooling water by controlling a temperature control unit on the basis of the temperature of source hydrogen flowing into a junction at which the source hydrogen and a circulating gas are mixed such that the temperature of a source/recirculated hydrogen mixture that is mixed at the junction and that is supplied to the fuel cell stack is kept within a managed temperature range.

Abstract: In at least one embodiment, a purge system for a fuel cell stack is provided. The system comprises a blower, a differential pressure sensor and a purge valve. The blower delivers a recirculated gas back to the stack at varying electrical power levels and blower speeds. The differential pressure sensor senses pressure of the recirculated gas across the blower. The purge valve purges the recirculated gas based on at least one of a blower power level, a blower speed, and the pressure of the recirculated gas.

Abstract: A solid oxide fuel cell system (10) comprises a solid oxide fuel cell stack (12) and a gas turbine engine (14), a compressor (24) of the gas turbine engine (14) is arranged to supply oxidant to the cathodes (22) of the solid oxide fuel cell stack (12) and a fuel supply (32) is arranged to supply fuel to the anodes (20) of the solid oxide fuel cell stack (12). A portion of the unused oxidant from the cathodes (22) of the solid oxide fuel cell stack (12) is supplied back to the cathodes (22) of the solid oxide fuel cell stack (12). A portion of the unused fuel from the anodes (20) of the solid oxide fuel cell stack (12) is supplied to a combustor (52). A portion of the unused oxidant from the cathodes (22) of the solid oxide fuel cell stack (12) is supplied to the combustor (52) and the combustor (52) is arranged to supply exhaust gases to a first inlet (68) of a heat exchanger (66).

Abstract: A fuel cell system includes a pressure regulating valve for controlling a pressure of an anode gas, a purge valve for controlling a discharge amount of an anode off-gas, the purge valve being configured to change an opening area thereof at least on two stages, a pulsation operation control means configured to control the pressure regulating valve so that the pressure of the anode gas in a fuel cell when a load is high becomes higher than when the load is low, and so that the pressure of the anode gas is periodically increased and decreased at a predetermined load, and a purge valve control means configured to increase the opening area of the purge valve used during a descending transition operation so that the opening area becomes larger than the opening area used during other operations.

Abstract: A fuel cell system includes a fuel cell formed by stacking a plurality of power generation cells, and an oxygen-containing gas supply apparatus for supplying an oxygen-containing gas to the fuel cell. The oxygen-containing gas supply apparatus includes an oxygen-containing gas supply channel connected to an oxygen-containing gas inlet of the fuel cell for allowing the oxygen-containing gas to flow from an air pump into the oxygen-containing gas inlet, a branch supply channel branched from the oxygen-containing gas supply channel and which is opened to the inside of a fuel cell chamber, an oxygen-containing gas discharge channel for discharging an oxygen-containing off gas from the fuel cell, and an oxygen-containing off gas circulation channel one end of which is connected to the oxygen-containing gas discharge channel, and another end of which is connected to the oxygen-containing gas supply channel at a position upstream from the air pump.

Abstract: In a fuel cell system, a controller is programmed to control a first gas supply mechanism to deliver a first gas containing a fuel gas to a cathode in a pre-stop process performed at a system stop of the fuel cell system. The controller is programmed to control the first gas supply mechanism to stop the delivery of the first gas in a first state where a partial pressure difference between an anode and the cathode with respect to at least the fuel gas of remaining gases in the anode and in the cathode is reduced to or below a preset reference value.

Abstract: A fuel cell system including an ejector that merges a hydrogen gas to be supplied from a hydrogen tank to a fuel cell with a hydrogen-off gas exhausted from the fuel cell and supplies the resulting gases to the fuel cell. A hydrogen pump that pressurizes the hydrogen-off gas in a hydrogen circulation flow path and sends the hydrogen-off gas toward a hydrogen supply flow path and a control unit that controls, when the pressure of the hydrogen-off gas in the hydrogen circulation flow path is increased by the ejector and the hydrogen pump, the pressure of the hydrogen gas to be supplied to the ejector and the pressure increase of the hydrogen-off gas realized by the hydrogen pump so that the pressure increase of the hydrogen-off gas realized by the ejector is 0 or higher.

Abstract: The potential energy from a hydrogen tank is used in a gas jet pump, which draws in anode waste gas via an inlet and recirculates it to an anode inlet. To ensure that this system operates effectively even under low loads, a part of the waste gas is supplied to a compressor, and the compressed waste gas is supplied to the motive jet inlet of a gas jet pump, which may be the same one to which the hydrogen from the tank is also supplied. Different gas jet pumps may also be used, for the hydrogen from the tank on the one hand, and the compressed waste gas on the other hand.

Abstract: A fuel cell system includes: a fuel cell to consume a fuel and generate electric power; a feeder for feeding a circulating fluid including the fuel to the cell; a collector for collecting the circulating fluid including unconsumed fuel from the cell; a first channel connecting the cell with the collector; a second channel connecting the collector with the feeder; and a third channel connecting the feeder with the cell. A mass ratio M2/M1 is less than or equal to 20 ppm in terms of hexadecane, where M1 is a total mass of the collector and the first, second and third channels, and M2 is a mass of organic substances eluted into the circulating fluid or an equivalent therefor, while the collector and the first, second and third channels are immersed in the circulating fluid or equivalent at a temperature TH1 for a certain time.

Abstract: Systems and methods are provided in which ammonia is used as a fuel source for solid oxide fuel cell systems. In the various aspects a high temperature fuel cell stack exhaust stream is recycled through one or more separation or conversion devices to create a purified recycled fuel exhaust stream that is recycled back into the fuel inlet stream of the high temperature fuel cell stack. In various aspects a nitrogen separator may remove nitrogen from the recycled fuel cell stack exhaust stream, a water separator may remove water from the recycled fuel cell stack exhaust stream, and/or an ammonia reactor and hydrogen separator may be used to condition the fuel inlet stream of the high temperature fuel cell stack. In a further aspect a molten carbonate fuel cell and/or Sabatier reactor may be used to condition the fuel inlet stream of the high temperature fuel cell stack.

Abstract: A combined generation system according to one embodiment of the present invention comprises: a natural gas synthesizing apparatus for receiving coal and oxygen, generating synthetic gas by a gasifier, and permitting the synthetic gas to pass through a methanation reactor so as to synthesize methane; a fuel cell apparatus for receiving fuel that contains methane from the natural gas synthesizing apparatus and generating electrical energy; and a generating apparatus for producing electrical energy using the fluid discharged from the fuel cell apparatus

Abstract: A fuel cell with a recovering unit and a method of driving the same are disclosed. In one embodiment, the fuel cell includes i) an electric generator to generate electricity based on electrochemical reaction, ii) a recovering unit to recover and mix the fuel, unreacted fuel, and gas and water produced by the electrochemical reaction, and supply the mixed fuel to the electric generator, wherein the recovering unit comprises a valve, configured to discharge gas, which is selectively opened and closed depending on the operation of the fuel cell. With this configuration, the gas or the fuel is not introduced into the electric generator, even though the recovering unit is inclined or turned over. Further, even though the fuel cell is not in use for a long time, the mixed fuel is prevented from evaporating through the discharging pipe.

Abstract: The present application relates to a fuel cell system and a method for driving same, which can produce stable electricity, enhance load following capability, and simultaneously increasing fuel utilization rate and energy efficiency by separately managing a base load and a load following of a fuel cell, and the fuel cell system according to one embodiment of the present application comprises: a molten carbonate fuel cell for generating electricity by using fuel; a reaction gas for shifting discharge gas into water gas; a buffer tank for storing the water gas; and a driving device which is actuated by using the water gas that is stored and provided from the buffer tank.

Abstract: A fuel cell system includes a fuel cell stack, an ejector in fluid communication with the fuel cell stack and having a converging-diverging (CD) nozzle with a hydrogen feed nozzle and a recirculation conduit upstream of a throat of the CD nozzle, and a thermal source configured to heat the ejector. A hydrogen supply assembly for a fuel cell system includes an ejector having a converging-diverging (CD) nozzle and a mixing chamber upstream of the CD nozzle. The mixing chamber has a recirculation conduit and a hydrogen feed nozzle. A thermal source is configured to heat the ejector. A method of controlling a hydrogen supply device for a fuel cell includes, in response to detecting a heating condition at fuel cell start up, controlling a thermal source to heat an ejector upstream of an anode stack to prevent ice formation in the ejector.

Abstract: An exemplary fuel cell system includes a cell stack assembly having a plurality of cathode components and a plurality of anode components. A first reactant blower has an outlet situated to provide a first reactant to the cathode components. A second reactant blower has an outlet situated to provide a second reactant to the anode components. The second reactant blower includes a fan portion that moves the second reactant through the outlet. The second reactant blower also includes a motor portion that drives the fan portion and a bearing portion associated with the fan portion and the motor portion. The motor portion has a motor coolant inlet coupled with the outlet of the first reactant blower to receive some of the first reactant for cooling the motor portion.

Abstract: A method for operating a fuel cell system involves operating the fuel cell with recirculation of anode exhaust gas below a predefined maximum load limit of the fuel cell and operating the fuel cell without recirculation of the anode exhaust gas between the load limit and the full load of the fuel cell.

Abstract: A fuel cell system (1), especially in a motor vehicle, is provided with at least one fuel cell (18) for generating electric current from anode gas and cathode gas, with at least one reformer (22) for generating anode gas from oxidant gas and fuel. At least one residual gas burner (26) is provided for burning anode waste gas with cathode waste gas. A recycling device (48) is provided for recycling burner waste gas to the reformer (22).

Abstract: A fuel cell system for generating a hydrogen test pulse includes a fuel cell stack having an anode inlet in fluid communication with a hydrogen source via a fuel spending line, a cathode inlet in fluid communication with an oxidant source, and an anode outlet and a cathode outlet in fluid communication with an exhaust line. An electric pressure regulator is in fluid communication with the fuel spending line. An overpressure valve is in fluid communication with an overpressure line, which is in fluid communication with the fuel spending line between the electric pressure regulator and the fuel cell stack. A hydrogen sensor is in communication with the exhaust line, and is configured to measure the hydrogen test pulse.

Abstract: A fuel cell system includes a fuel cell stack and a humidifier. The humidifier includes an unreacted gas inlet port connected to an end of an unreacted hydrogen discharge pipeline, which is connected at the other end to a hydrogen outlet port of the fuel cell stack, such that the unreacted hydrogen discharged from the fuel cell stack via the hydrogen outlet port is led by the unreacted hydrogen discharge pipeline into the humidifier. The humidifier regulates the humidity and concentration of the unreacted hydrogen led thereinto, and the unreacted hydrogen is then discharged from the humidifier.

Abstract: In various aspects, systems and methods are provided for operating a molten carbonate fuel cell, such as a fuel cell assembly, with increased production of syngas while also reducing or minimizing the amount of CO2 exiting the fuel cell in the cathode exhaust stream. This can allow for improved efficiency of syngas production while also generating electrical power.

Abstract: In various aspects, systems and methods are provided for operating a molten carbonate fuel cell assembly at increased power density. This can be accomplished in part by performing an effective amount of an endothermic reaction within the fuel cell stack in an integrated manner. This can allow for increased power density while still maintaining a desired temperature differential within the fuel cell assembly.

Abstract: Systems and methods are provided for capturing CO2 from a combustion source using molten carbonate fuel cells (MCFCs). The fuel cells are operated to have a reduced anode fuel utilization. Optionally, at least a portion of the anode exhaust is recycled for use as a fuel for the combustion source. Optionally, a second portion of the anode exhaust is recycled for use as part of an anode input stream. This can allow for a reduction in the amount of fuel cell area required for separating CO2 from the combustion source exhaust and/or modifications in how the fuel cells are operated.

Abstract: A reactant processing module with a hybrid autothermal reformer (HASR) can allow for control of both the amount of cathode recirculation and the amount of water sent to the HASR. At the beginning of life of the fuel cell, reactant processing module can operate on full cathode recirculation. As the fuel cell begins to age and become less efficient, the amount of nitrogen-heavy, vitiated air from the fuel cell cathode can be monitored by a control system and restricted using a valve. In order to compensate for the aforementioned restriction, the rate of input of the external air supply is increased to the HASR and the deficit in water is supplied in liquid form from a water reservoir and turned to steam within the HASR. The amount of liquid water input from the water reservoir that meets the need for continued efficient operation is relatively small.

Abstract: In various aspects, systems and methods are provided for operating a molten carbonate fuel cell assembly at increased power density. This can be accomplished in part by performing an effective amount of an endothermic reaction within the fuel cell stack in an integrated manner. This can allow for increased power density while still maintaining a desired temperature differential within the fuel cell assembly.

Abstract: Systems and methods are provided for capturing CO2 from a combustion source using molten carbonate fuel cells (MCFCs). The fuel cells are operated to have a reduced anode fuel utilization. Optionally, at least a portion of the anode exhaust is recycled for use as a fuel for the combustion source. Optionally, a second portion of the anode exhaust is recycled for use as part of an anode input stream. This can allow for a reduction in the amount of fuel cell area required for separating CO2 from the combustion source exhaust and/or modifications in how the fuel cells are operated.

Abstract: Systems and methods are provided for capturing CO2 from a combustion source using molten carbonate fuel cells (MCFCs). At least a portion of the anode exhaust can be recycled for use as a fuel for the combustion source. Optionally, a second portion of the anode exhaust can be recycled for use as part of an anode input stream. This can allow for a reduction in the amount of fuel cell area required for separating CO2 from the combustion source exhaust and/or modifications in how the fuel cells can be operated.

Abstract: An enclosed separator unit for incorporation into a gas supply device of a fuel cell system, to separate liquid from the gas supply device, includes a separator for separating the liquid. A housing encloses the separator unit which is arranged in a gas space 21 in the housing and/or is in thermal contact with the gas space. A line system is provided for discharging the liquid from the separator, and at least one fluid dynamically active functional component is arranged in the line system, in the gas space 21.

Abstract: The present invention provides a method of converting a hydrocarbon into H2 and a carbon material comprising substantially no CO2, whereby the H2 is used by a fuel cell to generate electrical energy and the carbon material is collected. The method includes heating a hydrocarbon and a catalyst in a reactor to form H2 and a carbon material comprising substantially no CO2. A fuel cell is operated to generate electrical energy and heat using the H2 formed in the reactor. The step of heating is repeated using the heat generated in the fuel cell. The present invention also provides a system for converting a hydrocarbon into H2 and a carbon material comprising substantially no CO2, whereby the H2 is used by a fuel cell to generate electrical energy and the carbon material is collected.

Abstract: A fuel cell system that determines the concentration of hydrogen gas in an anode loop. The fuel cell system includes at least one fuel cell, an anode inlet, an anode outlet, an anode loop, a source of hydrogen gas and an injector for injecting the hydrogen gas. First and second pressure sensors are provided in the anode loop and are spaced a known distance from each other. A controller responsive to the output signals from the first and second pressure sensors filters the sensor signals from the first and second pressure sensors and determines the concentration of hydrogen gas in the anode loop based on the time difference between the filtered sensor signal from the first pressure sensor and the filtered sensor signal from the second pressure sensor.

Abstract: The fuel cell system is simplified and made more compact while providing the favorable recirculation of hydrogen-containing off-gas regardless of the increase or decrease in its flow rate. The fuel cell system is provided with: a cell unit that generates electricity by means of separating hydrogen-containing gas and oxygen-containing gas from each other while placing in flow contact to each other; and a recirculation mechanism for recirculating to the cell unit hydrogen-containing off-gas discharged from the cell unit. The fuel cell system has a flow rate determination unit that determines whether or not the hydrogen-containing gas fed to the cell unit is less than a predetermined flow rate; and a gas feeding pressure varying mechanism that cause the pressure of the hydrogen-containing gas to vary to increase and decrease when it is determined that the hydrogen-containing gas fed to the cell unit is less than the predetermined flow quantity.

Abstract: A fuel cell system includes a fuel cell stack, a heavy hydrocarbon fuel source, and a fractionator configured to separate light ends from heavy ends of a heavy hydrocarbon fuel provided from the heavy hydrocarbon fuel source.

Abstract: Processes and systems for operating molten carbonate fuel cell systems are described herein. A process for operating a molten carbonate fuel cell system includes providing a hydrogen-containing stream comprising molecular hydrogen to an anode portion of a molten carbonate fuel cell; controlling a flow rate of the hydrogen-containing stream to the anode such that molecular hydrogen utilization in the anode is less than 50%; mixing anode exhaust comprising molecular hydrogen from the molten carbonate fuel cell with a hydrocarbon stream comprising hydrocarbons, contacting at least a portion of the mixture of anode exhaust and the hydrocarbon stream with a catalyst to produce a steam reforming feed; separating at least a portion of molecular hydrogen from the steam reforming feed; and providing at least a portion of the separated molecular hydrogen to the molten carbonate fuel cell anode.

Abstract: A solid oxide fuel cell system (10) comprises a solid oxide fuel cell stack (12) and a gas turbine engine (14). The solid oxide fuel cell stack (12) comprises a plurality of solid oxide fuel cells (16). The gas turbine engine (14) comprises a compressor (24) and a turbine (26). The compressor (24) supplies oxidant to the cathodes(22) of the fuel cells (16) via an oxidant ejector (60) and the oxidant ejector (60) supplies a portion of the unused oxidant from the cathodes (22) of the fuel cells (16) back to the cathodes (22) of the fuel cells (16) with the oxidant from the compressor (24). The fuel cell system (10) further comprises an additional compressor (64), an additional turbine (66), a cooler (70) and a recuperator (72). The compressor(24) supplies oxidant via the cooler (70) to the additional compressor(64) and the additional compressor(64) supplies oxidant to the oxidant ejector (60) via the recuperator (72).

Abstract: A flow battery system and method are provided. The flow battery system includes a first battery stack including a first half-cell, a first pressure feed system, including at least a first storage tank and a first booster tank to store a liquid electrolyte, designed to generate a first booster pressure in the first booster tank sufficient to force the liquid electrolyte to be fed from the first pressure feed system through the first half-cell, and a return system to return the liquid electrolyte from the first half-cell to the first pressure feed system. The return system may include a gravity feed system returning liquid electrolyte from the first half-cell to a collection tank, and a pump to return the collected liquid electrolyte from the collection tank to the first storage tank. The pressure feed flow battery system may have a two-tank, divided 2-tank, or four-tank flow battery configurations.

Abstract: Processes and systems for operating molten carbonate fuel cell systems are described herein. A process for operating a molten carbonate fuel cell system includes providing a hydrogen-containing stream comprising molecular hydrogen to an anode portion of a molten carbonate fuel cell; controlling a flow rate of the hydrogen-containing stream to the anode such that molecular hydrogen utilization in the anode is less than 50%; mixing anode exhaust comprising molecular hydrogen from the molten carbonate fuel cell with a hydrocarbon stream comprising hydrocarbons, contacting at least a portion of the mixture of anode exhaust and the hydrocarbon stream with a catalyst to produce a steam reforming feed; separating at least a portion of molecular hydrogen from the steam reforming feed; and providing at least a portion of the separated molecular hydrogen to the molten carbonate fuel cell anode.

Abstract: An apparatus for delivering a primary fuel stream to a fuel cell stack is provided. The apparatus includes an ejector that is configured to receive the primary fuel stream from a fuel supply. The apparatus is further configured to receive the recirculated fuel stream from the fuel cell stack to provide a combined fluid stream for delivery to the fuel cell stack. The ejector includes an elastic conduit for varying a flow of the combined fluid stream based on a power level of the fuel cell stack.

Abstract: The fuel cell system includes: at least one fuel cell adapted to generate electrical energy from a fuel gas and an oxidizer gas; a fuel feed duct provided for supplying the fuel cell with fuel gas, the fuel feed duct including an upstream part and a downstream part; a Venturi effect ejector including a high pressure inlet, a low pressure inlet and an outlet, the upstream part of the fuel feed duct being connected to the high pressure inlet of the ejector and the downstream part extending between the ejector outlet and the fuel cell; an off-gas recirculation duct extending between the fuel cell and the low pressure ejector inlet so that, in the presence of a stream of fuel gas coming from the upstream part of the fuel feed duct and passing through the ejector, the ejector draws up off-gas from the recirculation duct and ejects it into the downstream part mixed with the stream of fuel gas coming from the upstream part; a control circuit and a valve arranged in the upstream part of the fuel feed duct and arra

Abstract: A gas-supply passage (6) via which anode gas is supplied to a fuel cell unit (2) and a gas-discharge passage (12) via which anode gas is discharged from the fuel cell unit (2) are connected via a communication passage (30). Circulation pump (32) switches the communication state of the communication passage between a closed state and an opened state. Circulation pump (32) causes a gas flow from the gas-discharge passage to the gas-supply passage when the communication passage (30) is in the opened state. The communication passage (30) is normally closed, and it is opened when a predetermined condition related to the operation state of the fuel cell unit (2) is satisfied.

Abstract: The present invention relates to a fuel cell system for vehicles and a method for controlling the same which stably maintains an output of a fuel cell by precisely estimating a recirculated hydrogen amount to a stack. A fuel cell system according to the present invention may include: a stack comprising a plurality of unit cells for generating electrical energy by electrochemical reaction of a fuel and an oxidizing agent; a blower for recirculating a gas exhausted from the stack so as to supply the gas back to the stack; an ejector for recirculating the gas exhausted from the stack, receiving hydrogen so as to mix the hydrogen to the recirculated gas, and supplying the mixture to the stack; a sensor module for detecting a driving condition of the vehicle; and a control portion for controlling operations of the blower and the ejector by using the driving condition of the vehicle and performance maps of the blower and the ejector.

Abstract: A fuel cell system having an air quality sensor suite includes a fuel cell having an anode and a cathode, a fuel source providing a fuel flow, a fuel flow rate sensor having a fuel flow rate sensor output, a fuel flow control device, a fuel oxidizer flow conduit, a first mixing region coupled to the fuel source and the fuel oxidizer flow conduit, an anode chamber coupled to the anode, a combustion oxidizer flow conduit, a second mixing region coupled to the combustion oxidizer flow conduit, and at least one oxidizer flow rate sensor having an oxidizer flow rate sensor output. The system further includes at least one oxidizer pump, an air quality sensor having an air quality sensor output, and a control system coupled to the fuel flow rate sensor output, the oxidizer flow rate sensor output, and the air quality sensor output.

Abstract: A fuel cell system includes: a reformer configured to generate a hydrogen-containing gas through a reforming reaction by using a raw material and steam; a raw material supply device configured to supply the raw material to the reformer; a steam supply device configured to supply the steam to the reformer; a temperature detector configured to detect a temperature of the reformer; a fuel cell configured to generate electric power by using the hydrogen-containing gas; a combustor configured to combust the hydrogen-containing gas discharged from the fuel cell to heat the reformer; and a controller configured to, while controlling the raw material supply device such that the temperature detected by the temperature detector becomes a target temperature, control the steam supply device such that a change rate of a steam supply amount to the reformer becomes less than a change rate of a raw material supply amount to the reformer.